Device for automatically controlling the fore and aft inclination of aircraft



Aug. 15, 1939. s. z. VON MANTEUFFEL 2,169,982

' DEVICE FOR AUTOMATICALLY CONTROLLING THE. FORE 1 Filed Jan, 26, 1939 AND AFT INCLINA'I'ION OF AIRCRAFT mientak Patented Aug. 15, 1939 LING THE FORE AND OF AIRCRAFT AFT INCLINATION Gert Zoege von Manteuflel, Berlln-Dahl'em, Gerassignor to Aslrania-Werke A. G., a cormany notation of Germany Application January 26, 1939, Serial No. 252,961

. In'Germany August 1'1, 193'! v I 14 Claims. (01. 24 4-18 a The present invention is concerned with aeaction of which is dependent upon the inclinais made dependent on a fore andaft inclinometer or altimeter, additionally sensitive to an air-speed responsive device. The alleged object of such an arrangement was to ensure further to the stabilizing of the airplane the maintenance of 4 an air speed compaflble with safety of flight, should the propelling mechanism fail. This prior suggestion, however, had the disadvantage that the superimposed control values acted oppositely one toithe other and thus'detrlmentally aflected one another; v

- In the present invention this is avoided by the use of a delayed-action means for slowly compensating the effect of the control values serving craft. With thls'arrangement long-period deviations from the requisite inclination are gradually T rendered ineffective and the position of the elevator isadjusted soas tomaintain the speed of the aircraft.

According to a further part ofthe invention the controlling force acting in dependence upon the flying attitude of the craft is made'to operate the fore and aftinclination regulating means (e. g. the elevator) through the medium of two measuring systems working in opposition to one another, but. one of which includes time delay means so that it lags somewhat behind the other -measuring system whereby the control force or movement of. those measuringsystems is compensated when a change of theflying speed causes a permanent tilt of the craft. This resultant ,force or movemmt is superimposed upon the control force or movement emanating from the control responsive to the speed of flight of the craft. Therefore, any change/in the tore and aft inclination, or altitude, respectively, will cause a deflection of the elevator in order to restore the former position of flight, but upon disturbances tion of the craft, and this jet pipe'can be associated with and actuated by a gyro-vertical provided for stabilizing the longitudinal inclination of the craft. The jet pipe relay would have; in the usual manner, a pair of nozzles arranged op posite to the discharge end of the jet pipe so asv tion the said two nozzles are arranged tocom-- municate respectively with the two chambers of a primary differential pressure meter, the pressure fluid being delivered directly to these chambers from the nozzles; and the said nozzles also respectively have communication (constricted as compared with their communications with thechambers of the primary difierential pressure meter) with the two chambers of asecondary differential pressure meter which is arranged oppositely to the primary diflerential meter so that v the eflfect produced by the primary'meter is 01)- posed by the delayed effect produced by the secondary meter, and means are provided to transmit the resultant movement of the actuating members-of the two meters to a secondary pressure fluid relay upon which is also impressed the controlling effect of .the air speed responsive device. The delayed efiect of the secondary meter Further aims, objects and advantages will appear from a consideration. of the description, as

well as the accompanying drawing showing an embodiment of the invention for illustrative purposes.

The drawing diagrammatically illustrates a verticalsection through an automatic control device constructed according to' the invention and in which the elevator of an aeroplane is automatically controlled by an air speed responsive member on the control valve of which there is super-- imposed a second control value which is seii-- adjusting; or compensating and is supplied by a gyro-vertical. I I

In the annexed drawing, the arrow i denotes "the direction of flight 'of the aircraft. A gyrovertical 2 controls a jet pipe relay 5 (which is pivotable about an axis 6) through a disc having a cam slot 3 in which works the follower of a lever 4 associated with the jet pipe 5.

Pressure fluid (supplied from any suitable source) flows through the jet pipe 5, in the direction of the arrow 5, to the nozzle orifices l. latter are directly connected through conduits 9, 9 respectively to the two chambers of a primary differential pressure meter 8.

Cross-over conduits l0, ID, are branched ofl from the conduits 9, 9, and include throttling or constricted parts H, H. The conduits l3, ill lead respectively to the two chambers i2 of a secondary differential pressure meter. The said two chambers l2 each have an auxiliary chamber l3 communicating therewith.

The chambers 8 of the primary diflerential pressure meter are each provided with a diaphragm 8 and these diaphragms are interconnected by a bar I4. The chambers l2 are similarly provided with covering diaphragms l2 which are interconnected by a bar it.

The bars l4 and i5 are connected by a difflerential linkage system it and a lever I! to a jet pipe relay I8 on the one hand, and to a damping gyroscope [9 on the other hand.

Pressure medium supplied from a suitable source is adapted to flow through the jet-pipe of the relay IS in the direction of the arrow I3, and this jet pipe is arranged to oscillate about a pivot 23 under the action .of a lever 2i which, in turn, is operated by a diaphragm 23 loaded by a spring 22. A set screw 22' is provided for setting the tension of the spring 22 to correspond with the desiredspeed of flight.

The diaphragm 23 forms the closure of a housing 24 which is connected through a pressure conduit 25 with a Pitot tube 26. The pressure set up by the relative wind acts on the tube 23 in the direction of the arrows 21.

The rotor of the damping gyroscope i3 rotates in the direction of arrow i9 about vertical pivot points 28 mounted in a prescesslon frame 29. The latter is adapted to oscillate about horizontally-arranged pivot points 30, the axis of which is parallel to the direction of flight of the aircraft.

Attached to the frame 28 is a frontwardly-directed lever 32 which is connected on the one hand with a dashpot piston 33, and on the other hand with a lever 34 pivotally connected to the lever II.

by a link 35 which is capable of movement in the directions of the two arrows 36 and 33'.

Fluid issuing from the jet pipe It enters the nozzle orifices 31 and passes through conduits 39 to the two sides of a servo-motor piston 39. The latter is movable in a casing or cylinder 43 and controls the elevator 43 of the aircraft through a linkage 4|, 42.

The operation of the device described is as follows.

Should the attitude of the air craft be temporarily changed for short periods, the differential pressure set up by the movements of the jet pipe relay 5 will only have a substantial effect on the diaphragms 3'. The delay in the passage of fluid to the chambers l2, l2, caused by the constrictions H, II and by the provisions of these chambers with auxiliary capacities I3, is so great that short period fluctuations in pressure will not affect the diaphragms l2, l2. Consequently the bar 15 does not change its position and only the bar 14 moves, this bar controlling the second The jetpipe relay through the levers I1, 35 and 2!. Pressure will then be exerted on the piston 33 in accordance with the change of attitude of the aircraft, and this will cause an adjustment of the elevator 43.

The movement of the jet pipe l3 will be additional affected by the gyroscope l9, so long as the aircraft has an angular velocity around its axis. The gyroscope I9 is responsive to angular velocities derived from changes in the fore'and aft inclination of the craft when it produces a precession beat which is damped by the piston 33.

-A third control value which vaiifects the jet pipe i8 is represented by an impulse dependent on the relative wind speed of the craft. The spring 22 is so adjusted by means of the screw 22 that it balances the dynamic pressure in the housing 24 when the relative wind speed has a predetermined value. Any deviation from this speed is transformed into a. movement of the diaphragm 23, and causes an adjustment of the relay l9 and a corresponding movement of the elevator.

If the speed of travel decreases or the relative wind speed otherwise varies, the pressure acting on diaphragm 23 drops and, as a result, the jet pipe l8 moves upwards and discharges a greater amount of pressure fluid into the upper orifice 31 than into the lower one. The servomotor piston 39 then moves to the right and the elevator moves downwardly. This causes the nose of the aircraft to dip by an amount sufficient to compensate the fall in speed, due, for example, to the failure of the engine.

This adjustment of the elevator first counteracts the control value given by the jet pipe relay 5 as the result of the longitudinal inclination of the aircraft. After a short period, however, sufficient fluid passes through the appropriate constriction II to one meter chamber i2, whereupon the bar I5 is moved.

If the chamber systems 3 and I2 are of the same construction, the transmission lever is pivotally connected to the rod l3 at the middle of the latter. This results in the displacement of the lever l4 in relation to the transmission lever l1, ceasing after a short while due to the movement of the bar i5.

The accompanying drawing illustrates a case in which the aircraft has an excessive speed for a long period. The initial consequence is that the jet pipe relay l3, which is moved downward by the diaphragm 23, imparts an upward movement to the elevator. The aircraft will strive to right itself but will at first be prevented from doing so by the gyroscope 3 and the relay 3 controlled thereby. Thus, when the inclination of the aircraft is modified the jet pipe relay 5 comes to rest in front of the lower orifice I, resulting in an over pressure on the lower diaphragm l and an upward movement of the bar l4.

The full effect of the control value which is dependent on the relative wind speed cannot come fully into play in view of the fact that the jet pipe relay I3 is also moved upwards by this action. After a short time, however, the pressure in the chamber I2 is equalized with that in the chamber 3, whereupon the bar l5 between the diaphragms l2 moves downwards in opposition to v the movement of the bar l4. In this way the lever I1 is restored to its mean position, so that the full dynamical pressure in the chamber 24 acts on the jet pipe l3. V

The yielding nature of the control characteristic imparted by the gyro-vertical enables the aicaasa obtained-that the fore and aft inclination is used as ameasure for the balance of energy in stabilizing the-.craft. Under suitable circumstances, an apparatus responsive to changes in altitude, e. g. a statoscope, could replace the inclinometer or gyro-vertical.

Furthermore, abrupt control movements are prevented by the added control characteristic of the dam-ping gyroscope l9, thus further increasmeans comprising a first meter adapted for diing the safety of the automatic control device.

' It will be understood that I desire to .comprehend within ,my invention such modifications as may be clearly embraced within the claims and scope of my invention.

What I claim is: 1 v 1. Apparatus for automatically controlling the fore and aft inclination of an aircraft, comprisyice, and a device responsive to changes in the' fore and aft inclination of the aircraft for additional control of said means for varying the elevator position, said inclination-responsive device including primary means for providing a primary actuation and means adapted to act with a time delay relative to said primary means for counte'racting the effect of the latter.

2. Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising a device for actuating the elevator'of the aircraft, means responsive to changes in the airspeed for operating said elevator-actuating device, control means responsive to changes in the fore and aft inclination of the aircraft for operating said elevator-actuating device in opposition to said air I speed-responsive means, and delayed-action means for compensating the effect of said control means.

3. Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising a device for actuating the elevator of the aircraft, means responsive to change in the air speed of the craft for imposing a control value on said elevator-actuating. device, control means responsive to a flight characteristic of the aircraft for imposing a. second control value on said elevatoractuating device, and delayed-action means for compensating, said second control value.

4; Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising a device for actuating the elevator of the aircraft, means responsive to'changes in the air speed for operating said elevator-actuating device, control means responsive to changes in the attitude of the aircraft for operating said elevator-actuating device in'opposition' to said air speed-responsive means, and delayed-action means for compensating the effect of saidcontrol-means.

-5, Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising a device for actuatingthe elevator of the aircraft, means responsive to'changes in the air speed for operating said elevator-actuating device, and controlmeans responsive to changes in the inclination ofthe aircraft for operating said ele- 1 vator-actuating device in opposition to said air speed-responsive means, said control means com-' and aft inclination of an aircraft, comprising a device for actuating the elevator of the aircraft, means responsive to .changes in the air speed for operating said elevator-actuating de vice, and control means responsive to changes in the inclination of the aircraft for operating said elevator-actuating device in opposition to said air speed-responsive means, said control rect operation in response to achange in the inclination of the aircraft, a second meter adapted for delayed operation in response to "said change in inclination, means for balancing the operation of said first and second meters, a jet pipe relay for supplying working fluid in variable relative amounts to said first and second meters, and means for pivoting said jet'pipe relay in accordance with changes in the inclination'of the aircraft.

7. Apparatus for automatic control of the fore and aft inclination ofan aircraft, comprising a device for actuating the elevator of the aircraft,.mea.ns responsive to changes in the'air speed for operating said elevator-actuating device, and control means responsive to. changes in the inclination of the aircraftfor operating said elevator-actuating device in opposition to said air speed-responsive means, said control means comprising balanced devices adapted respectively for'rapid and delayed response to a change in inclination of the aircraft, a gyroscope adapted to be controlled by changes in said inclination, and a jet pipe relay adapted to be operated by said gyroscope so as to actuate said balanced devlces.-

8. Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising a device for actuating the elevator of the aircraft, means responsive to changes in the air speed for operating said elevator-actuating device, and control means responsive to changes in the inclination of the aircraft for operating said elevator-actuating device in opposition to said air speed-responsive means, said control means comprising a jet pipe relay adapted to be moved 9."Apparatus according to claim 8, wherein the said-means for retarding the action of fluid on the deformable walls comprise adjustable constrictions in the'conduits leading to each of one of said pairs of oppositely-located chambers.

10, Apparatus according'to claim 8, wherein the means for retarding the action of fluid on the deformable walls comprise an auxiliary chamber communicating with each chamber of one pair of oppositely-located chambers.

11. Apparatus for controlling automatically the fore and aft inclination of an aircraft, comprising a servo-motor, a relay for supplying pressure ,fluid to either side of the piston of said servo motor, a pairof oppositely-acting control members, linkage means for transmitting the result-v ant ot the actions 1 said control member to said relay, means one ble by pressure fluid for each of said control embers, conduit means for leading pressure fluid to each of said fluid pressure operable means, relay means for supplying pressure fluid to said conduits, means responsive to a flight characteristic of the aircraft for controlling said relay, andmeans for delaying the action of one of said pressure-operable means.

12. Apparatus for automatic control of the fore and aft inclination of anaircraft, comprising a servo-motor with its piston operatively connected to the elevator of the aircraft, a jet pipe relay for controlling the operation of said servo-motor, means responsive to changes in the air speed of the aircraft for controlling the jet pipe of said jet pipe relay and means responsive to changes in the fore and aft inclination of the aircraft for imposing a second control on said jet pipe in opposition to the air-speed responsive control.

13. Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising a servo-motor having its piston operatively connectedto the elevator of the aircraft, a jet pipe relay for controlilng the. operation of said servomotor, a Pitot tube, a chamber having a diaphragm forming a wall thereof communicating with said Pitot tube, a mechanical connection be tween said diaphragm and the jet pipe of said jet pipe relay, adjustable means for controlling the displacement of said diaphragm, means responsive to changes in the fore and aft inclination of the aircraft for operating said jet pipe in opposition to said diaphragm, and means for 10 delaying the action of said inclination-responsive means on the jet pipe.

14. Apparatus for automatic control of the fore and aft inclination of an aircraft, comprising means for operating the elevator oi the aircraft 1 a turn gyroscope for imposing a third control on 20 said elevator in response to rotation about the transverse axis of the aircraft.

GERT ZOEGE von mm. 

